Dual-channel magnetic isolator for 100 Mbps signal isolation
The STMicroelectronics STISO621TR is a dual-channel, unidirectional digital isolator using magnetic coupling to provide galvanic isolation up to 4000 Vpk. It supports data rates up to 100 Mbps with typical rise/fall times of 2 ns, making it suitable for isolating high-speed digital interfaces such as SPI, UART, or GPIO lines in industrial automation, motor drives, and power-conversion systems. The supply range spans 3 V to 5.5 V, and the part is rated for operation from -40°C to 125°C, covering industrial and extended-temperature environments.
100 Mbps data rate and 42 ns propagation delay — bus timing margin
The 100 Mbps data rate and 42 ns maximum propagation delay (tpLH/tpHL) define the timing budget for the isolated channel. For a 50 MHz SPI clock, the 42 ns delay adds about two clock cycles of latency round-trip — acceptable for most sensor readback and configuration transactions, but worth verifying against the master's setup/hold window. The 3 ns maximum pulse-width distortion keeps the duty cycle nearly intact, which matters for PWM or one-wire protocols where edge symmetry is critical.
50 kV/µs CMTI — noise rejection in switching environments
The minimum common-mode transient immunity is 50 kV/µs. This rejects fast voltage transients across the isolation barrier.